I'm use mikeal/request to make API calls. One of the API's I use most frequently (the Shopify API). Recently put out a new call limit, I'm seeing errors like:
Exceeded 6.0 calls per second for api client. Slow your requests or contact support for higher limits.
I've already gotten an upgrade, but regardless of how much bandwidth I get I have to account for this. A large majority of the requests to the Shopify API are within async.map() functions, which loop asynchronous requests, and gather the bodies.
I'm looking for any help, perhaps a library that already exists, that would wrap around the request module and actually block, sleep, throttle, allocate, manage, the many simultaneous requests that are firing off asynchronously and limit them to say 6 requests at a time. I have no problem with working on such a project if it doesn't exist. I just don't know how to handle this kind of situation, and I'm hoping for some kind of standard.
I made a ticket with mikeal/request.
I've run into the same issue with various APIs. AWS is famous for throttling as well.
A couple of approaches can be used. You mentioned async.map() function. Have you tried async.queue()? The queue method should allow you to set a solid limit (like 6) and anything over that amount will be placed in the queue.
Another helpful tool is oibackoff. That library will allow you to backoff your request if you get an error back from the server and try again.
It can be useful to wrap the two libraries to make sure both your bases are covered: async.queue to ensure you don't go over the limit, and oibackoff to ensure you get another shot at getting your request in if the server tells you there was an error.